problems and promises of deterministic extended range forecasting1

The past 20 years have encompassed remarkable scientific and technical advances in the atmospheric and oceanic sciences which herald a new era for deterministically predicting atmospheric behavior. Many of the key innovations were directly influenced, if not originated by Harry Wexler during his very productive career. This paper will deal with a critique of recent progress in modelling the atmosphere-ocean system, some of the newly exposed problems, and the needs and expectations for the future.